Bryston PowerPac 120, Owner'S Manual

Page: 12 / 12

ENGINEERING CHANGE ORDER #771
MODELS
AFFECTED:
PowerPac 300*
SUBJECT:
Modification at input and output of +/- 33V regulators located on
daughter & Regulator board and on Output Devices board
IS A SAFETY STANDARDS RE-
EVALUATION REQUIRED (Y/N)?
(See foot note)
MODELS: Logical character search strings using AND/OR/NOT operators with "asterisk" and "question mark" wildcards, or list ALL models explicitly.
Priority 1: Immediate and unconditional; current production halted until new parts or procedures available. All finished units retrofitted.
Priority 2: All units in production (i.e. all unfinished units) will use new parts or procedures as soon as they become available.
Priority 3: New parts or procedures will be used as soon as they become available AND as soon as existing parts are depleted or declared dead stock.
Priority 4: Alternate parts MAY be used as demand requires.
SAFETY STANDARDS EVALUATIONS: All changes must be assessed to determine their possible impact on Safety Standards approvals and the need to either resubmit
specific documentation, or the entire unit, for updated certification. If it is determined that Safety Standards approvals may be affected, then a Safety Standards Approval
Report must be attached to this ECO detailing steps taken to update necessary approvals.
ECO13.dot WRP 29 Jan 2004
ISSUE DATE ENGINEER(s) PRIORITY STARTING SERIAL No.
2004-08-26 FN 1 PP300-000091
n
DETAILED DESCRIPTION of, and REASONS for, CHANGE
Due to a report of an open circuit in two re-setable fuses (RXE-010) on an Output Devices Board
causing high DC offset and subsequent speaker damage, these parts are being removed and
replaced as described below:
1- On Output devices board (CBP300-OD/1.0) remove two re-set-able fuses F2 & F3 replace them
with two jumpers (R139 & R140).
2- On Daughter & Regulator board (CBP300-DR/R1) remove two pair series of capacitors
C308,C307 & C608,C607 and replace them with two diodes 1N914, D604 & D304 (PART#
DI1N914B000)
3- In PowerPac 300 with Option On Daughter & Regulator board (CBP250-DR/7.0) remove two
capacitors C307,C607 and replace them with two diodes 1N914 (PART# DI1N914B000). Also in the
same board replace two re-set-able fuses F3 & F2 with two jumpers (R605 & R305)
DOCUMENTS :
DOCUMENT NAME DOCUMENT DESCRIPTION ENGR(s) STATUS
ECO-771-6.pdf Daughter & Regulator board Assembly Instruction without option FN COMPLETE
ECO-771-5.pdf Daughter & Regulator board Assembly Instruction with option FN COMPLETE
ECO-771-1.pdf +33V & + 16 Regulator Schematic FN COMPLETE
ECO-771-2.pdf -33V & - 16 Regulator Schematic FN COMPLETE
ECO-771-4.pdf Assembly Instruction of Output Devices board FN COMPLETE
ECO-771-3.pdf Output Devices Schematic FN COMPLETE
Brstonltd01\EngPDFs\Enginee
ring\PowerPac 250 or 300
\P300-M1&M2 Updated Part List FN IN PROCESS
ENGINEERING PURCHASING PRODUCTION
APPROVAL
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